1. Field of the Invention
This invention relates to devices used to measure and indicate the elapsed time of usage of a medical device and more especially to devices that prevent the usage of a medical device without the initiation of time measurement and to devices that record and indicate elapsed time at the completion of use of a medical device.
2. Description of the Related Art
Many products including common packaged food items and medical products have a finite shelf life defining a time period beyond which such products are rendered ineffective, and may even cause illness or injury. Thus, a need to track or measure the elapsed time from first use to expiration of such products has been identified. In response to such need, various elapsed time indication devices have been developed. An example of such time measuring and indication device is the device disclosed in published U.S. patent application 20040240324 by Ibitsky et al. Ibitsky teaches a device that measures time by means of measuring the migration of a fluid of a known viscosity from a first chamber to a second chamber. Upon the expiration of a predetermined time which is based of the rate of flow of the fluid, an indication such as an “expired” indication is displayed by the device. U.S. patent application 20040240324 is incorporated herein in its entirety by reference.
Further, in various industrial applications, human exposure to certain conditions such as a radioactive condition is know be tolerable or acceptable when less than a predetermined exposure and is know to be intolerable or unacceptable when greater than a predetermined exposure. Thus a need to track the duration and quantity of exposure has been identified. In response to such need, various exposure levels monitoring devices and various exposure elapsed time measuring and indication devices have been developed. Examples of such devices are disclosed in U.S. Pat. Nos. 4,903,254, 5,058,088, 5,364,132, 5,446,705, 5,602,804, 5,633,835, 5,699,326, 5,715,215, 5,719,828, 5,785,354, 5,822,280, 5,862,101, 5,873,606, 5,930,206, 5,947,369, 5,957,458, 6,295,252, 6,452,873, and 6,796,065. The listed patents are incorporated herein by reference.
In spite of the advances and advantages of the inventions described above, to the applicant's knowledge, no time indication device exists that is directly connected to routinely used medical devices such as an intravenously inserted tube and needle assembly (IV). It also noted that leaving an IV inserted into a patient beyond a predetermined generally accepted time period is believed to contribute to causing nosocomial infections or phlebitis in the patient. Further no such devices known to prevent use of a medical apparatus without the starting the timing of such timing device. Further, no such devices are known to record the point at which such devices are stopped in their time measuring function.